us about the reputation of david petraeus and why did he have to quit, gary? >> reporter: a couple things. this is a man who literally rewrote the book on how the military deals with counter insurgency. he changed the strategy in iraq and turned that war around, largely responsible for the surge in afghanistan that arguably turned that war around. people will be studying what he wrote in terms of counterinsurgency for decades. it's become taught at military campuses around the country. why now? there are senate hearings into the benghazi attack next week that. may have something to do with it. one of his subordinates, another general, is now being court-martialed in the united states and he was quoted as saying if i'm going down, i'm taking others with me. we do not know the relationship, but it is a curious matter of timing. also we don't know who the woman is, but if it was a subordinate, a diplomat or someone within the military, then that would put him in a situation as the leader of the cia where he could be compromised, perhaps one reason he chose to ste